1. Field of the Invention
The present invention relates to an image processing apparatus for processing an image, an image forming apparatus, an image processing method, and a computer-readable recording medium on which an image processing program is recorded.
2. Description of the Related Art
Among image forming apparatuses such as a digital color copying machine and a multifunction peripheral, some image forming apparatuses have a two-color mode for outputting a two-color image besides a full-color mode for outputting a full-color image and a monochrome mode for outputting a monochrome image.
In the two-color mode, the image forming apparatus outputs all chromatic colors in an original document or a chromatic color (e.g., red), which a user designates in advance by extracting the chromatic color from the original document, in the chromatic color (e.g., red) designated by the user in advance and outputs portions of other colors in the original document in an achromatic color (black). Consequently, the image forming apparatus can obtain, while reducing an amount of use of color materials to be smaller than that in the full-color mode, an output image having better color expression than that in the monochrome mode.